title: Hydroxyurea in sickle cell disease--a study of clinico-pharmacological efficacy in the Indian haplotype.
abstract: There is clinical variability in the presentation of sickle cell disease among Indians. Vaso-occlusive crisis is common among non-tribal patients. Hydroxyurea, induces fetal hemoglobin (HbF) synthesis and reduces the clinical severity of sickle cell disease but individual patients have a variable response. This study was undertaken to investigate the efficacy and safety of hydroxyurea in Indians with severe manifestations where the beta(s) gene is linked to the Arab-Indian haplotype and is associated with higher HbF levels. Seventy-seven patients (29 adult sickle homozygous, 25 pediatric sickle homozygous, 23 adult sickle beta-thalassemia) selected for hydroxyurea therapy were evaluated for clinical, hematological, biochemical and genetic parameters and were followed for 24 months. Ninety-eight point seven percent of the sickle chromosomes were linked to the Arab-Indian haplotype, 27% of patients had associated alpha thalassemia and 65% were Xmn I +/+. Seventy-eight percent of the patients had no further crises after starting hydroxyurea. This effect was accompanied by a significant increase in HbF (p<0.001), but this increase was variable in individual cases. There was also an increase in gamma gene mRNA expression in the few cases so studied. Hemoglobin levels increased significantly (p<0.001) resulting in the cessation of blood transfusions. Leucopoenia was observed in one patient. Hydroxyurea was effective in reducing the clinical severity in Indian patients who initially had higher HbF levels and the presence of ameliorating factors, such as alpha-thalassemia and the Xmn I polymorphism. Hydroxyurea therapy with careful monitoring can thus change the quality of life of Indians with sickle cell disease.
authors.affiliation: National Institute of Immunohaematology, KEM Hospital Campus, Parel, Mumbai, India.
authors.forename: Khushnooma
authors.initials: K
authors.lastname: Italia
authors.forename: Dipty
authors.initials: D
authors.lastname: Jain
authors.forename: Sushma
authors.initials: S
authors.lastname: Gattani
authors.forename: Farah
authors.initials: F
authors.lastname: Jijina
authors.forename: Anita
authors.initials: A
authors.lastname: Nadkarni
authors.forename: Pratibha
authors.initials: P
authors.lastname: Sawant
authors.forename: Sona
authors.initials: S
authors.lastname: Nair
authors.forename: Dipika
authors.initials: D
authors.lastname: Mohanty
authors.forename: Kanjaksha
authors.initials: K
authors.lastname: Ghosh
authors.forename: Roshan
authors.initials: R
authors.lastname: Colah
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005319:Fetal Hemoglobin / Q000096:biosynthesis / Q000235:genetics; D006239:Haplotypes; D006451:Hemoglobin, Sickle / Q000235:genetics; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D007194:India; D008297:Male; D055815:Young Adult; D055544:beta-Globins / Q000235:genetics; D017086:beta-Thalassemia / Q000097:blood / Q000188:drug therapy / Q000235:genetics
chemical_list: D006451:Hemoglobin, Sickle; D055544:beta-Globins; D005319:Fetal Hemoglobin; D006918:Hydroxyurea